Apparatus and Method for Casting Concrete Wall Elements

ABSTRACT

An apparatus for casting concrete wall elements, which together form a wall, running along a curvature at least in sections, of a container, in particular of a fermenter for biogas plants, comprising a horizontal foundation, to which several horizontally extending bounding elements are attached, which between them form fields to be cast with concrete, several formwork elements, which are detachably secured to at least a few bounding elements, which form formwork surfaces, which are opposite each other in a field and which are aligned at an angle with respect to the vertical, which in the erected state form the face side surfaces of adjacent wall elements, that face each other, wherein the formwork elements each have at the formwork surfaces at least one receiving device, and wherein at least one end of at least one reinforcing element to be cast in the concrete is secured in each receiving device of formwork surfaces, which are opposite each other in a field.

The invention relates to an apparatus and a method for casting concrete wall elements, which together form a wall of a container, in particular, among others, of a fermenter for biogas plants, running along a curvature at least in sections. Fluids or other substances are filled into such typically cylindrical fermenters for fermentation in biogas plants. For constructing the container it is typical to first cast a base of concrete on the foundation. Then a plurality of substantially cuboidal wall elements, likewise of cast concrete, can be erected on this base. In the erected state, together, the wall elements form the polygon-like container wall. Due to the container wall running along a curvature, the wall elements for this must be provided with angled face side wall surfaces so that adjacently erected elements can be placed with their face surfaces next to each other without forming a gap. To avoid forming undesired gaps, the face sides must be precisely formed. The same is true for the remaining dimensions of the elements because the leak tightness of the container, in particular, is of crucial importance. In addition, adjacent wall elements must be connected together. For this purpose, it can be necessary to provide reinforcing rods or similar in the wall elements, and appropriate connections in the elements so that the reinforcing rods of adjacent elements can be connected together.

Thus, it is necessary to produce relatively complex wall elements with high accuracy, preferably at the installation site of the wall.

Starting from the described prior art as a background, the object of the present invention is therefore to provide an apparatus and a method of the initially named type, with which the concrete wall elements can be provided on-site in a simple and precise manner.

The invention achieves this object by the subject matter of claim 1 and the subject matter of claim 19. Advantageous embodiments are found in the dependent claims, the description and the drawings.

The invention achieves this object with an apparatus for casting concrete wall elements of the initially named type, comprising:

-   -   a horizontal foundation, upon which several horizontally         extending bounding elements are fastened; the area between the         bounding elements forming fields for the wall elements to be         cast with concrete,     -   several formwork elements that are detachably fastened to at         least a few bounding elements that form formwork surfaces lying         opposite each other in a field and aligned at an angle to the         vertical, and that represent face side surfaces of adjacent wall         elements that face each other in the erected state,     -   wherein the formwork elements at the formwork surfaces each have         at least one receiving device, and wherein one end of at least         one reinforcing element to be cast in the concrete is fastened         in receiving devices of formwork surfaces lying across from each         other in a field in each case.

The invention achieves the object also with a method for casting concrete wall elements, which together form a wall of a container running along a curvature at least in sections, in particular of a fermenter for a biogas plant, comprising the steps:

-   -   casting a horizontal concrete base for the container at the         installation site of the container,     -   fastening several horizontally extending bounding elements to         the base that bound the fields for the wall elements to be cast         with concrete,     -   casting the wall elements in concrete, in the fields that are         defined by the bounding elements,     -   forming the wall of the container by erecting the wall elements         cast in the fields.

With the method according to the invention, a high-value formwork is available at the installation site of the container due to the bounding elements; using the formwork the wall elements of the container can be cast with concrete. In the process, in a first work step the first half of the wall elements of the container are cast in the fields, and subsequently erected, and in a second work step, the second half of the wall elements of the container are cast in the fields and subsequently erected.

According to a further embodiment of the method it can be provided that several formwork elements are detachably fastened at least to a few bounding elements which form formwork surfaces that lie opposite each other in a field and that are aligned at an angle to the vertical, said formwork surfaces represent the face sides of adjacent wall elements facing each other in the erected state, and that the formwork elements at the formwork surfaces each have at least one receiving device, and wherein one end of at least one reinforcing element to be cast into the concrete is fastened in receiving devices of formwork surfaces lying opposite each other in a field.

The bounding elements run in the horizontal direction on the level foundation and form a grid of fields to be filled with concrete. The bounding elements can be beams, for example steel or aluminum beams. Their position can be fixed using diagonals and/or braces so that a dimensionally exact position is attained. A separation layer, for instance a separation film, is provided on the bottom of the field to prevent the poured concrete from bonding to the foundation that also consists of concrete, for instance. After casting, the wall elements lie on the foundation with their front sides or back sides provided as outer or inner walls of the container. Then, they are lifted from the foundation together with the formwork elements, and the formwork elements are removed from the wall elements. Next, the wall elements are set upright, and erected for forming the container wall, wherein adjacent elements are connected at their face side surfaces.

The formwork surfaces running in the horizontal direction along the bounding elements form the surfaces abutting each other at the joints between adjacent wall elements in the erected state. The container wall can run along a circle, at least in sections. It is then formed as a polygon due to the wall elements. The angled formwork surfaces ensure that the joints between the side surfaces of adjacent wall elements can be closed. The wall elements have essentially plane parallel front and back sides, which each can be formed essentially as rectangles. Thus, except for the angled side surfaces, the wall elements are substantially cuboid.

Great flexibility is attained due to the detachable fastening of the formwork elements to the bounding elements. Therefore, for different container sizes different formwork elements are fastened to the bounding elements which represent the appropriate different angled face side surfaces of the wall elements. For this purpose, chamfered flat sheets (made of steel, aluminum or similar) can be fastened, welded on for instance, to the bounding elements, for instance, at their bottom, laterally and in sections, or continuously upward. The side formwork elements then have a recess at their bottom with which they are placed on the chamfer of the flat sheets. The formation of the recess in the formwork elements determines the angle of the formwork surface. At their top, the formwork elements can be fixed by the head plates connected to the bounding elements, for example.

Because receiving devices, in which the reinforcing elements that are necessary for the reinforcing of the wall are placed, are already provided in the formwork elements, the reinforcing is already prepared in a simple manner during casting. After erecting, reinforcing elements of adjacent wall elements can then be easily connected together.

Naturally, several receiving devices can be provided at each formwork surface. Accordingly, several reinforcing elements then run in a field between opposite receiving devices.

Projections (for example formed by triangular strips) can be provided at the bottom and/or top of the formwork elements, e.g. at the possibly provided head surfaces, which create appropriate chamfers on the wall element. Furthermore, in addition to the formwork elements having angled formwork surfaces, further formwork elements that represent the top and bottom of the wall elements can naturally be provided in a field. Depending on the desired shape, these can form vertical formwork surfaces, in particular. In addition, fastening elements that are also cast and allow receiving the cast wall elements while erecting the wall, can be disposed in the fields of the apparatus. It is also possible to dispose elements in the fields to be cast with concrete that represent openings in the wall elements to be produced, for example for hatches, safety flaps, etc.

Using the apparatus according to the invention and the method according to the invention it is possible to produce wall elements in a simple and flexible manner, and to form the container walls at the installation site of the container. In the process, it is guaranteed that precise quality standards are maintained during the production of the elements.

A concrete steel reinforcement can be provided according to applicable rules. According to one embodiment, the reinforcing elements can be reinforcing rods or reinforcing cables. The reinforcing elements can also be reinforcing tubes, in particular reinforcing empty tubes or respectively jacket tubes, for respectively receiving a reinforcing rod or reinforcing cable. The reinforcing elements and in particular the reinforcing rods or respectively reinforcing cables can be made of steel. The reinforcing rods or respectively reinforcing cables of adjacent wall elements are connected together after erecting the elements. With the reinforcing tubes, the reinforcing rods or reinforcing cables can be inserted before or after pouring the concrete into the tubes. The connection, especially of reinforcing rods or respectively reinforcing cables, can be performed by welding, for example. Reinforcing cables that are connected to the reinforcing rods can form loops in the face area of the wall elements. Loops of adjacent elements can then be placed above one another and connected together by a reinforcing rod guided through the loops.

In a particularly practical manner, the foundation itself can be formed by the base of the container to be erected. The container base provides a planar foundation well suited for pouring the concrete wall elements thereupon. The container base is therefore, also, of concrete that is cast on site.

The reinforcing elements, in particular, the reinforcing rods or reinforcing tubes, can run curved between the receiving devices of opposing formwork surfaces. In this, the axis of curvature can run in particular in the horizontal direction. They can run in particular in a circular arc shape between the receiving devices. The curvature required in each case is specified by an appropriate alignment of opposing receiving devices.

According to a further embodiment, at least one of the receiving devices, in particular a few or all of the receiving devices located opposite each other in a field can each have a cylindrical element fixed in the formwork surface, wherein the reinforcing tube(s) are slipped onto the cylindrical element(s). Recesses can then be provided in the formwork elements, and the cylindrical element(s) are placed therein. After casting, the formwork elements with the cylindrical elements are removed from the wall elements. According to a further particularly simple embodiment, at least one of the receiving devices, in particular a few or all of the receiving devices located opposite each other in a field can each have a bore hole provided in the respective formwork surface, wherein the reinforcing rod(s) or reinforcing tubes are inserted into the bore hole(s). According to an alternative embodiment, the at least one receiving device, in particular a few or all of the receiving devices located across opposite other in a field can each have a sleeve fastened in the formwork surface, wherein the receiving rod(s) or receiving tubes are inserted into the sleeve(s). The sleeves can each have an outer surface tapering conically starting from the formwork surface. This facilitates removing the formwork after casting.

One or more of the reinforcing rods can have at least one, in particular at both ends, head having an expanded cross section with respect to the reinforcing rod. Such heads can be formed pot-like or solid. For fastening to the formwork elements, the rods with their heads can be inserted, e.g. in sleeves or boreholes in the formwork elements. For connecting reinforcing rods of adjacent wall elements, the heads can then be placed on one another, and for example, connected together by clamping. Such clamping can be formed, for example by two half-shells encompassing the heads that are fixed by a ring.

According to a further embodiment, at least one reinforcing rod can have at least one end a head having an expanded cross-section with respect to the reinforcing rod, and at least one other reinforcing rod can have at least at one end a shaped piece with an undercut, wherein for connecting the reinforcing rods of wall elements that are adjacent in the erected state, the head of the one reinforcing rod can be hooked into the undercut of the opposite reinforcing rod. In a particularly simple manner it is possible to provide each reinforcing rod at one end with a head, and with a shaped piece at the other end. However, it is also possible to provide a few of the reinforcing rods at both ends with a head and the other reinforcing rods at both ends with a shaped piece. The shaped pieces can, in a particularly practical manner, each have a keyhole opening through which the head of another reinforcing rod can be hooked into the respective undercut. In this manner, in the erected state, quasi-continuous rods are formed in the walls, wherein the rods of adjacent wall elements can be hooked into one another in a particularly simple manner. The respective heads or shaped elements can in turn be held in sleeves and/or bore holes in the formwork elements.

A further embodiment provides that at least one end region, in particular both end regions, of the reinforcing elements are encompassed in each case at least in sections, particularly completely, by a shaped element that forms a recess in the cast concrete wall element at the end region(s). Such shaped elements can be composed of rigid foam, for example. Recesses formed this way allow subsequent access in the region of the connection of two erected wall elements for fastening the reinforcing elements together, e.g. for a welding procedure or another type of connection. It is also possible to dispose shaped elements at a few or all of the formwork surfaces, which form joints in the cast wall elements. Sealing compound can be placed in such joints. The shaped elements can be bars for example, which are formed as half-rounds so that a cylindrical recess forms with assembled walls.

At least at one formwork surface, in particular at several or all, formwork surfaces, at least one projection can be provided, and at least one, in particular at several or all, other formwork surfaces at least one recess can be provided that corresponds to the at least one projection. During casting, the projection forms a recess, and the recess during casting forms the corresponding projection. With walls put together, this projection fits in a kind of block shear connector into the recess. This way, the walls and for example, joints provided therein, are connected together in a shear-resistant manner. The shape and the size of the projections and the recesses are matched to the selected embodiment of the formwork surfaces and reinforcing elements. To prevent poured concrete from penetrating under the formwork elements, furthermore, at least one film can be provided in the area of contact between the formwork elements and the foundation. According to a further embodiment, at least one film is disposed on the foundation of at least one field, in particular under several or respectively all fields. Such films are used to seal the container formed by the wall elements. According to a further embodiment in this regard, the film can furthermore extend at least over the formwork surfaces of the at least one field, in particular over several or respectively all fields. In the erected state of the wall elements, these films cover the top and bottom sides of the wall elements.

According to a further embodiment, the apparatus can have at least one retainer, which holds a fastening element for fastening further devices to at least one wall element, at least partially in a field of concrete to be cast. The fastening element is therefore cast at least partially in the concrete. The corresponding retainer is fastened to the formwork elements or bounding elements before casting the concrete. The fastening element can be, for example an anchor element for fastening a railing to the container wall. Such an anchor can be formed by a bolt, for example, to which a railing is fastened or on which it is suspended. However, it is also possible that the fastening element is a rail for fastening a film of a cover of the container. The film of a film covering of such a container is placed in rails having a U-shaped cross-section, for example. Finally, they can be clamped in a known manner, for instance by a tube placed in the rail, and thus fastened.

To precisely align the heavy and large wall elements to each other while erecting, the apparatus can have an assembly aid. Thus, the at least one of the formwork surfaces can preferably have a conical shaped element, which forms a preferably conical recess in the associated wall element, wherein at least one other formwork surface, for example an opposite one, is provided with a threaded connector to be cast in the concrete, in that a preferably conical shaped element can be screwed in that corresponds to the recess in the cast wall element. The cone can be a cone or a truncated cone.

The invention relates also to one or more concrete wall elements, produced with the apparatus according to the invention, if necessary, in the erect state, connected to each other to build a wall.

An exemplary embodiment of the invention is explained in the following in more detail using the figures. The figures show schematically in:

FIG. 1 a top view of an apparatus according to the invention according to a first exemplary embodiment,

FIG. 2 a top view of an apparatus according to the invention according to a second exemplary embodiment,

FIG. 3 a section along the line a-a in FIG. 1 according to a further exemplary embodiment,

FIG. 4 side views of two concrete wall elements cast with the apparatus according to the invention for illustrating a bracing,

FIG. 5 a section along the line a-a in FIG. 1 according to a further exemplary embodiment,

FIG. 6 a cross-sectional view of a connection of the wall elements produced according to FIG. 5,

FIG. 7 a longitudinal sectional view of the representation from FIG. 6,

FIG. 8 a section along the line a-a in FIG. 1 according to a further exemplary embodiment,

FIG. 9 a connection of wall elements produced according to FIG. 8 in a further side sectional view,

FIG. 10 a section along the line a-a in FIG. 1 according to a further exemplary embodiment,

FIG. 11 two sectional views of a connection of the wall elements produced according to FIG. 10,

FIG. 12 a section along the line a-a in FIG. 1 according to a further exemplary embodiment,

FIG. 13 a section along the line a-a in FIG. 1 according to a further exemplary embodiment,

FIG. 14 a section along the line a-a in FIG. 1 according to a further exemplary embodiment,

FIG. 15 a section along the line a-a in FIG. 1 according to a further exemplary embodiment,

FIG. 16 a section along the line a-a in FIG. 1 according to a further exemplary embodiment,

FIG. 17 a section along the line a-a in FIG. 1 according to a further exemplary embodiment,

FIG. 18 a section of a wall element according to a further exemplary embodiment,

FIG. 19 a section for illustrating the function of the assembly aid represented in FIG. 18, and

FIG. 20 sectional views for illustrating an assembly aid according to a further exemplary embodiment.

The same reference numbers refer to the same objects in the figures unless indicated otherwise. Using the apparatus according to the invention, containers can be erected in sizes from 15 to 50 m in diameter and 5 to 12 m in height, for example. FIG. 1 shows the base 10 that is cast in concrete at the installation site, for a fermenter to be erected for a biogas plant. Seen in a top view, it is circular and has a flat surface. FIG. 1 also shows several bounding elements 12 that are beams composed of steel, aluminum or another material in the example shown. The beams are placed in the grid spacing and fixed by diagonals 14 and braces 16 for fastening on the base 10 so that a dimensionally precise positioning is attained. Next, the beams 12 are fastened on the base 10 in a manner to be described in more detail. Fields 18 to be cast with concrete are defined between the beams. By filling the fields 18 with concrete, wall elements for the container are produced in two work cycles. After the first concrete pouring procedure, the first half of the wall elements are mounted on the base, which is schematically indicated in FIG. 1 for the wall elements 20. The wall elements 20 form a wall of the container running in a polygon-like manner along a circular track. Next, the second half of the wall elements 20 are cast in the fields 18, and the wall is correspondingly completed. FIG. 2 shows the case of a particularly large container with very high walls. In this case, it is necessary to enlarge the base 10 by a small area to be able to produce the wall elements in two work steps.

The sectional view in FIG. 3 shows a first exemplary embodiment of the apparatus according to the invention. A support beam 12 can be seen. Beveled flat steels 22 are welded to this beam in sections or continuously using a welding connection 24. The flat steels 22 and with them also the beams 12 are fixed on the base 10 using dowel bars 26, merely indicated schematically in FIG. 3, and corresponding screws. Also shown in FIG. 3 are formwork elements 28, made of wood for example, that have a machined recess 30, for instance, on their bottom. The formwork elements 28 extend over the entire length of each respective beam 12. The formwork elements 28 are engaged with the recesses 30 on the chamfer of the flat steels 22. The formwork elements 28 are held at their top on the entire length using a head plate 32 supplied with trimming strips. The head plate 32 is screwed to the beam 12 using screws 34. As a result, the formwork elements 28 are detachably connected to the beams 12. They form formwork surfaces 36 aligned at an angle α to the vertical and opposite each other in a field 18. These formwork surfaces 36 form the face side surfaces of adjacent wall elements, that face each other in the erected state of the wall elements. With the polygon-like set-up of the wall elements 20 shown in FIG. 1, it is assured due to their angled formation that the gap between adjacent wall elements 20 can be closed. Because the corresponding required inclination of the face sides depends on the diameter of the container, the formwork elements 28 are adapted to the respective required inclination by different machining at their foot. In addition, in the represented example, a triangular strip 38 that creates a chamfer in the concrete, is fastened in each case to the formwork elements 28 at the lower end. A corresponding chamfer is formed in the upper region of the field 38 by projections 40 of the head plate 32.

As receiving devices, the formwork elements 28, shown in FIG. 3, have at their formwork surfaces 36 cylindrical elements 42 inserted in a recess. In the example shown, an end of a reinforcing tube 44 to be cast in concrete, in the represented example a jacket tube 44, of steel, plastic or aluminum for example, is fastened in the receiving devices of formwork surfaces 36 located opposite each other in a field 18. An appropriate alignment of the cylinder elements 42 guarantees that the jacket tubes 44 run along a circular arc in a field 18. Here, the circular axis runs in the horizontal direction. This is shown in the upper part of FIG. 4 as an example. The cast wall element 20 is shown in a side view and the jacket tube 44 cast therein is shown with dotted lines. Here, a plurality of such jacket tubes 44 or other reinforcing elements can be disposed in the described manner in a field 18 for casting in concrete. The tubes 44 are already cut precisely to length at the factory. Before the installation of the tubes 44, the lower reinforcement that is required for the respective wall elements 20 is installed at the construction site.

After casting of the wall elements in the fields 18, the head plates 32 are released and the wall elements together with the formwork elements 28 and the receiving devices 42 are lifted upwards out of the fields 18. Next, the formwork elements 28 are pulled laterally from the wall elements 20. Afterwards, reinforcing rods for example, composed of steel for instance, can be guided through the reinforcing tubes 44. For fastening reinforcing rods of adjacent wall elements 20, it can be necessary to guide these out of the wall elements 20, as shown in the lower section of FIG. 4. In the regions marked with the arrows, adjacent reinforcing rods can be connected, as will be explained below in more detail using an example. The lower part of FIG. 4 shows a particular connection wall element 20′ to be cast using the apparatus according to the invention for clamping the elements 20 shown in the upper part of FIG. 4. Two such opposite connection wall elements 20′ can be supplied in a container wall, for example. The jacket tubes 44′, shown with dotted lines, can be cast into the wall. Now, if reinforcing rods are guided through the jacket tubes 44 of the elements 20 in the erected state, that end in the connection element 20′ and are guided laterally out of it through the jacket tubes 44′, as shown at the bottom in FIG. 4, then a clamping of the reinforcing rods, and therefore the entire container wall can take place, in that the rods at their exits from the connection elements 20′ are subjected to an appropriate tractive force.

FIG. 5 shown an alternative embodiment to the representation in FIG. 3. In contrast to the representation in FIG. 3, the formwork elements 28 have ring shaped sleeves 46 as receiving devices that are held in appropriate recesses of the formwork elements 28. Starting from the formwork surfaces 36, the sleeves 46 have a conically tapering outer surface. This simplifies the removal of the formwork. In the example shown, steel reinforcing rods 48 are inserted in the sleeves 46. The reinforcing rods 48 are welded to a pot-like head 50 via a steel disk 52 with a larger diameter. The reinforcing rods 48 are placed with their heads 50 into the sleeves 46, and thus in turn, are placed circular arc-like in the fields 18. For connecting the reinforcing rods 48 with the erected wall elements 20, that is still to be explained, a recess is required that in the example shown is formed by a shaped element 54 composed of rigid foam in the concrete. The shaped elements 54 extend beyond the entire height of the wall elements. This does not have to be case. The shaped elements 54 are released after casting the concrete, thereby leaving a recess. FIGS. 6 and 7 show the connection of the heads 50 of the reinforcing rods 48, shown in FIG. 5. For this purpose, the wall elements 20 are placed together so that the heads 50 of the reinforcing rods 48 of opposite wall elements abut each other. Then, half shells 56 are placed over the heads 50 and securely fixed using a ring 58.

FIG. 8 shows a section of a further embodiment of the apparatus according to the invention. In contrast to the exemplary embodiment shown in FIG. 5 for instance, the reinforcing rods 48, in the example shown on the left in FIG. 8, are inserted without a head into a sleeve 46 of the formwork elements 28. The sleeve 46 in turn, has a conical tapering outer shape, thereby making it easier to remove the formwork from the concrete. The right part of FIG. 8 shows an even simpler embodiment, in which the reinforcing rods 48 are inserted directly into a recess 60 in the formwork elements 28. These boreholes 60 each extend only approximately halfway through the thickness of the formwork elements 28. In addition, also shown in FIG. 8 are, in turn, the shaped elements 54 which in the region of the ends of the reinforcing rods 48 form a recess in the concrete. In the example shown, these do not extend over the total height of the wall elements to be cast. FIG. 9 shows a possible connection of the reinforcing rods 48 of adjacent wall elements 20 produced according to FIG. 8. In the end region of the reinforcing rods 48 that are freely accessible due to the shaped elements 54, round steel rods 62 are applied to the reinforcing rods 48 as a typical welding joint according to DIN, and welded as a grouting. Subsequently, the joint left by the shaped element can be closed using grout, for example or similar.

FIG. 10 shows a further alternative of the apparatus according to the invention. In contrast to the embodiment shown in FIG. 5 for instance, the end of one of the reinforcing rods 48 has a solid head 50 with which it is seated in a corresponding recess 60 and the associated formwork element 28. It can be seen here that the recess 60 has a greater depth than the thickness of the head 50. With the head 50 completely inserted into the recess 60, a part of the recess 60 remains free on the side facing away from the end of the reinforcing rod 48. This in turn, is filled with a releasable shaped element 54, of rigid foam for example, which leaves behind a corresponding recess behind the head 50 in the cast wall element. At its opposite end, the reinforcing rod 48, as shown in FIG. 10 in the right part, for another reinforcing rod 48, has a shaped piece 64, which is welded to the reinforcing rod 48. The shaped piece 64 has a cavity 66 that is formed as an undercut, as shown by the dotted lines in FIG. 10. With the shaped piece 64, the reinforcing rod 48, in turn, is seated in a sleeve 46 in the formwork element 28. After casting the wall elements in the fields 18 and removing the formwork, the reinforcing rods 48 are connected together using their head pieces 50 and shaped pieces 64, as shown in FIG. 11. The left part of FIG. 11 shows a cross section of the erected wall element 20 in the area of the wall connection. The right part of FIG. 11 shows a view along the line a-a in the left part, wherein only the rear wall element 20 is shown. It can be seen here that the shaped element 64 has a keyhole opening 68, through which the adjacent reinforcing rod 48 with its head 50 can be inserted into the cavity 66, and can be lowered into the undercut so that the reinforcing rods 48 are quasi-continuous.

In the further example shown in FIG. 12, in contrast to the example shown for instance in FIG. 8, shaped elements, conventional galvanized sheet steel boxes 70 in the example shown, are fastened on the formwork surfaces 36, for example by bonding or tacking. In this example, reinforcing cables 72 which have loops 74 disposed in the boxes 70, are welded to reinforcing rods, for example. When casting the fields 18 with concrete, cavities are formed due to the boxes 70 that can extend, in particular, over the entire height of the wall elements 20. For connecting adjacent wall elements 20, the loops 74 are placed above one another and a reinforcing rod, not shown in detail in FIG. 12, is guided through the loops. Next, the joints formed by the boxes 70 can be filled with concrete.

FIG. 13 shows additions which can be necessary in the joint during the production of the plates. Shown as an example are formed half round strips 76 at the formwork surfaces 36 which, when the assembled wall elements 20 are assembled, form corresponding cylindrical joints, in which sealing material can be inserted before the final assembly. The strips can extend for example over the total height of the erected wall elements. To attain a shear-resistant connection of adjacent wall elements 20, the formwork elements 28 can further be provided with projections in the shape of block shear connectors 78 that typically do not extend over the entire height of the erected wall elements. When casting the fields 18, these form a corresponding recess. In the wall element that is opposite in the erected state, a projection corresponding to the recess can be formed, in that a recess 80 is provided in the formwork elements 28 as represented in the right part in FIG. 13.

FIG. 14 further shows a retainer 82 that is removed after casting the fields 18. The retainer 82 is connected to the formwork element 28 using screws 84. It supports a bolt 86 that is cast in the concrete as an anchor for connecting a railing of the container for example. The formation and function of such bolts 86 as anchors, for railing parts for example, is known. The right part of FIG. 14 shows the device for forming a bottom of the wall elements 20. The formwork element 28 has a corresponding vertically aligned formwork surface 36. The formwork element 28 is secured by a spacer 88. Because the cast concrete wall parts 20 are lifted out of the fields 18 perpendicular to the base 10, low friction of the spacer 88 with respect to the formwork beams 12 must be attained. Because concrete can run beneath the formwork beams 12 due to unevenness of the base 10, in the example shown in FIG. 14, film strips 90 are bonded to the base 10 on one side and to the formwork elements 28 on the other. Such films can also be provided on the entire base 10, and naturally also with the other exemplary embodiments. Films can be provided that in the erected state of a wall element cover in particular the top and/or bottom of the wall elements. Such films can be used later in particular also for sealing the container.

FIG. 15 shows a section along the line c-c from FIG. 1. The formwork surfaces 36 in this example form the top side of the wall elements 20. In the example shown, these are also formed at an angle. Rails 92 for example can be seen here fastened to the formwork elements 28, for the known connection of film coverings of such fermenters. Furthermore the left part of FIG. 15 shows that the film cover 90 covers the entire area of the wall elements 20. It can be detachably bonded to the formwork element 28, and can be anchored to the edges 94 using any type of connection that is appropriate for film. FIG. 15 further shows in more detail the connection 26 of the flat steels 22, and with it the beams 12, to the base 10. A tube 98 provided with an inner thread is welded to a disk 96. This tube 98 is adjustably guided in an inner thread of the flat steels 22. After precise alignment of the beams 12 on the base 10, an dowel bar 26 is anchored through the tube 98 into the concrete, thereby securing the position of the beams 12. The flat steels 22 can be provided with several holes next to each other with inner threads for the tube 98, in order to avoid possible difficulties arising during boring due to the cast and abraded base, for instance reinforcements or larger stones.

The FIGS. 16 and 17 each show an assembly aid for the apparatus with which the large and heavy concrete wall parts 20 can be safely guided up to the connection at the joint. One of the two represented formwork surfaces 36 has a shaped element 100 that extends tapering starting from the formwork surface 36. The shaped element 100 is hollow and is composed of metal or plastic for example, and is mounted on the formwork surface 36. In addition, a shaped element 102 correspondingly adapted to the shaped element 100 is screwed onto the formwork surface 36 along the axis 104. On the other formwork surface 36, in the erected state forming the opposite face side surface of the wall element 20, a corresponding threaded connection 106 is fixed via a screw 108 guided through the formwork element 28, and cast in the concrete. After casting and removing the formwork of the wall elements 20, conical recesses remain in the wall elements 20 corresponding to the conical form element 100. The shaped piece 102, after removing the formwork, is screwed into the threaded connection 106 of an opposing wall element, as is shown for example in FIG. 18 for the assembly aid from FIG. 17. For assembly, the shaped piece 102 can now be inserted into the corresponding conical recess in the opposing wall element 20. With this, a precise alignment of the walls is attained in a simple manner.

The embodiment shown in FIG. 17 corresponds largely to the embodiment according to FIG. 16. Here, however, in contrast a plate shaped spacer 110 is disposed between the conical elements 100, 102 in the formwork surface 36. The spacer plate 110 can be joined to the formwork element 28 by means of screws 112. The spacer 110 forms a shoulder 114 as is shown in FIG. 18. Due to the elongated shape of the recesses formed by the shaped element 100 and the spacer 110, this assembly aid can also be used for the wall connection shown in the FIGS. 10 and 11. The shoulder 114 at the assembly cone 102 shown in FIG. 18, permits in particular an insertion of the assembly cone 102 into a correspondingly shaped element 100, and subsequently a shifting of the assembly cone 102 into the shaped element 100 so that the wall connection according to the FIGS. 10 and 11 can also be produced without damage. This is illustrated in FIG. 19 by the arrow 120. Next, the required tolerances are to be adjusted for the individual parts. The shaped element 100 can be implemented for this purpose also in a simple shape for inserting an assembly cone, as is shown in FIG. 20. The right part of FIG. 20 shows a section along the line a-a of the left part of FIG. 20.

The embodiments according to the invention of the receiving devices and the other elements, including the assembly aids, can each be provided on a few or all formwork elements, and combined with each other in any arbitrary manner. The same is true for the embodiments according to the invention of the ends of the reinforcing elements. With receiving devices corresponding to each other, assembly aids or reinforcing elements, as shown for instance in FIGS. 10, 11, and 16 to 20, can have formwork elements opposing in a field for each of the corresponding receiving elements or respectively assembly aids. Correspondingly, the reinforcing elements running in the field can each be provided at their ends with the appropriately corresponding shapes.

The apparatus according to the invention permits a simple and flexible production of wall elements 20, even in inaccessible areas, and correspondingly, erecting the container walls on-site. 

1. An apparatus for casting concrete wall elements (20), which together form a wall, at least in sections running along a curvature, of a container, in particular a fermenter for a biogas plant, comprising: a horizontal foundation (10), on which several horizontally extending bounding elements (12) are fastened, which between them form fields (18) to be cast in concrete for the wall elements (20),—several formwork elements (28) that are connected to at least several bounding elements (12), which form formwork surfaces (36) that are located across from each other in a field (18) and are aligned at an angle (α) to the vertical, which represent the face side surfaces of adjacent wall elements (20) facing each other in the erected state, wherein the formwork elements (28) at the formwork surfaces (36) each have at least one receiving device (42, 46, 60), and wherein one end of at least one reinforcing element (44, 48, 72) to be cast in concrete is fastened in each the receiving devices (42, 46, 60) in opposing formwork surfaces (36) in a field (18).
 2. The apparatus according to claim 1, characterized in that the at least one reinforcing element is a reinforcing rod (48) or a reinforcing cable, or that at least one reinforcing element is a reinforcing tube (44) for receiving a reinforcing rod or a reinforcing cable.
 3. The apparatus according to claim 1, characterized in that the foundation (10) is the base (10) of the container.
 4. The apparatus according to claim 1, characterized in that at least one reinforcing element (44, 48, 72) runs curved between the receiving devices (42, 46, 60) of opposing formwork surfaces (36).
 5. The apparatus according to claim 1, characterized in that at least one of the receiving devices (42, 46, 60) has a cylindrical or conical element (42) fastened in the formwork surface (36), wherein the at least one reinforcing tube (44) is slid onto the at least one cylindrical element (42).
 6. The apparatus according to claim 1, characterized in that at least one of the receiving devices (42, 46, 60) has a bore hole (60) provided in the formwork surface (36), wherein the at least one reinforcing rod or the at least one reinforcing tube is placed into the at least one bore hole (60).
 7. The apparatus according to claim 1, characterized in that at least one of the receiving devices (42, 46, 60) has a sleeve (46) fastened in the formwork surface (36), wherein the at least one reinforcing rod or the at least one reinforcing tube is slid into the at least one sleeve (46).
 8. The apparatus according to claim 1, characterized in that the at least one reinforcing rod (48) has at least on one end a head (50) with a cross section expanded with respect to the reinforcing rod (48).
 9. The apparatus according to claim 1, characterized in that at least one reinforcing rod (48) on at least one end has a head (50) with an cross section expanded with respect to the reinforcing rod, and at least one other reinforcing rod (48) on at least one end has a shaped piece (64) with an undercut (66), wherein for connecting the reinforcing rods (48) of wall elements (20) adjacent in the erected state, the head (50) of the one reinforcing rod (48) can be hooked in the undercut (66) of the opposing other reinforcing rod (48).
 10. The apparatus according to claim 9, characterized in that the at least one shaped piece (64) has a keyhole opening (68), through which the head (50) of another reinforcing rod (48) can be hooked in the respective undercut (66).
 11. The apparatus according to claim 1, characterized in that at least one end region of the at least one reinforcing element (44, 48, 72) is surrounded at least partially by a shaped element (54), that represents a recess at the end region in the cast concrete wall element (20).
 12. The apparatus according to claim 1, characterized in that shaped elements (76) are disposed at least at a few of the formwork surfaces (36), and represent the joints in the cast wall elements (20).
 13. The apparatus according to claim 1, characterized in that at least one projection (78) is provided at least one formwork surface (36), and on at least one other formwork surface (36), at least one recess (80) is provided that corresponds to the at least one projection (78).
 14. The apparatus according to claim 1, characterized in that a film (90) is provided at least in the area of contact between the formwork elements (28) and the foundation (10) that prevents cast concrete from penetrating underneath the formwork elements (28).
 15. The apparatus according to claim 1, characterized in that at least one film is disposed on the foundation of at least one field (18).
 16. The apparatus according to claim 15, characterized in that the film extends further, at least over the formwork surfaces (36) of the at least one field (18).
 17. The apparatus according to claim 1, characterized in that it has at least one retainer (82) which holds a fastening element (86, 92) for fastening further devices to at least one wall element (20) at least partially in a field (18) to be cast with concrete.
 18. The apparatus according to claim 17, characterized in that the fastening element (86) is an anchor element (86) for fastening a railing to the container wall.
 19. The apparatus according to claim 17, characterized in that the fastening element (92) is a rail (92) for fastening a film of a cover of the container.
 20. The apparatus according to claim 1, characterized in that at least one of the formwork surfaces (36) has a preferably conical shaped element (100), which reproduces a preferably conical recess in the associated wall element (20), and that on at least one other formwork surface (36), a threaded connector (106) to be cast in the concrete is provided, into which in the cast wall element (20) a preferably conical shaped element (102) corresponding to the recess can be screwed.
 21. A method for casting concrete wall elements (20), which together form a wall, running at least in sections, along a curve, of a container, in particular of a fermenter for a biogas plant, comprising the steps: casting a horizontal base (10) from concrete for the container at the installation site of the container, fastening several horizontally extending bounding elements (12) onto the base (10) which between them define fields (18) for the wall elements (20) to be cast with concrete, casting the wall elements (20) of concrete in the fields (18), defined by the bounding elements (12), forming the walls of the container by erecting the wall elements (20) cast in the fields (18).
 22. The method according to claim 21, characterized in that in a first work step the first half of the wall elements (20) of the container are cast in the fields (18), and subsequently erected, and that in a second work step the second half of the wall elements (20) of the container are cast in the fields (18) and subsequently erected.
 23. The method according to claim 21, characterized in that several formwork elements (28) are detachably fastened at least to a few bounding elements (12), which form formwork surfaces (36) that are located across from each other in a field (18) and that are aligned at an angle (α) to the vertical, which in the erected state form face side surfaces of adjacent wall elements (20) facing each other, and that the formwork elements (28) at the formwork surfaces (36) each have at least one receiving device (42, 46, 60), and wherein one end of at least one reinforcing element (44, 48, 72) to be cast into the concrete is fastened in each receiving device (42, 46, 60) of formwork surfaces (36) lying opposite each other in a field (18).
 24. The method according to claim 23, characterized in that the at least one reinforcing element is a reinforcing rod (48) or a reinforcing cable, or that the at least one reinforcing element is a reinforcing tube (44) for receiving a reinforcing rod or reinforcing cable.
 25. The method according to claim 23, characterized in that the at least one reinforcing element (44, 48, 72) runs curved between the receiving devices (42, 46, 60) of formwork surfaces (36) opposite each other.
 26. The method according to claim 23, characterized in that with at least one of the receiving devices (42, 46, 60) a cylindrical or conical element (42) is fastened in the formwork surface (36), wherein the at least one reinforcing tube (44) is slid onto the at least one cylindrical element (42).
 27. The method according to claim 23, characterized in that at least one of the receiving devices (42, 46, 60) has a bore hole (60) provided in the formwork surface (36), wherein the at least one reinforcing rod or the at least one reinforcing tube is slid into the at least one bore hole (60).
 28. The method according to claim 23, characterized in that at least one of the receiving devices (42, 46, 60) has a sleeve (46) fastened in the formwork surface (36), wherein the at least one reinforcing rod or the at least one reinforcing tube is slid into the at least one sleeve (46).
 29. The method according to claim 23, characterized in that the at least one reinforcing rod (48) on at least one end has a head (50) with a cross-section expanded with respect to the reinforcing rod (48).
 30. The method according to claim 23, characterized in that at least one reinforcing rod (48) at least one end has a head (50) having a cross-section expanded with respect to the reinforcing rod, and at least one other reinforcing rod (48) on least at one end has a shaped piece (64) with an undercut (66), wherein for connecting the reinforcing rods (48) of wall elements (20) that in the erected state are adjacent, the head (50) of the one reinforcing rod (48) is hooked in the undercut (66) of the other reinforcing rod (48) lying across from it.
 31. The method according to claim 30, characterized in that at least one shaped piece (64) has a keyhole opening (68), through which the head (50) of another reinforcing rod (48) is hooked in the respective undercut (66).
 32. The method according to claim 23, characterized in that at least one end area of the at least one reinforcing element (44, 48, 72) is surrounded at least partially by a shaped element (54), that forms a recess at the end region in the cast concrete wall element (20).
 33. The method according to claim 23, characterized in that shaped elements (76) are disposed at least a few of the formwork surfaces (36) that form joints in the cast wall elements (20).
 34. The method according to claim 23, characterized in that at least one projection (78) is provided on at least one formwork surface (36), and at least one recess (80) corresponding to the at least one projection (78) is provided on at least one other formwork surface (36).
 35. The method according to claim 23, characterized in that a film (90) is provided at least in the area of contact between the formwork elements (28) and the foundation (10) that prevents cast concrete from penetrating underneath the formwork elements (28).
 36. The method according to claim 21, characterized in that a film is disposed at least on the foundation of at least one field (18) before casting the concrete wall elements.
 37. The method according to claim 36, characterized in that the film extends further at least over the formwork surfaces (36) of the at least one field (18).
 38. The method according to claim 21, characterized in that at least one retainer (82) is provided that holds a fastening element (86, 92) for fastening further devices to at least one wall element (20) at least partially in a field (18) to be cast in concrete.
 39. The method according to claim 38, characterized in that the fastening element (86) is an anchor element (86) for fastening a railing to the container wall.
 40. The method according to claim 38, characterized in that the fastening element (92) is a rail (92) for fastening a film of a cover of the container.
 41. The method according to claim 23, characterized in that at least one of the formwork surfaces (36) has a preferably conical shaped element (100), which forms a preferably conical recess in the associated wall element (20), and that a threaded connector (106) to be cast in concrete is provided on at least one other formwork surface (36), into which, in the cast wall element (20), preferably conical shaped element (102) corresponding to the recess can be screwed. 